TW202003953A - Needle plate attachment and detachment mechanism and sewing machine including same - Google Patents

Abstract

An object of the invention is to improve the removability of a needle plate. A needle plate attachment and detachment mechanism comprises a needle plate which is provided on the head section of a sewing machine and is formed from a magnetic material, a magnet which is provided under the needle plate and holds the needle plate in place by magnetic force, and a magnetic force modifying mechanism which is connected to the magnet, and when activated causes relative movement of the magnet and the needle plate, thereby changing the magnetic force acting on the needle plate.

Description

Needle plate engagement and disengagement mechanism and sewing machine provided with the needle plate engagement and disengagement mechanism

The invention relates to a needle plate engagement and disengagement mechanism and a sewing machine provided with the needle plate engagement and disengagement mechanism.

The following Patent Document 1 describes a sliding plate device mounted on the head of a sewing machine. In this sliding plate device, the sliding plate body and the opening and closing plate constitute a sliding plate, and the opening and closing plate is fixed by the magnetic force of the magnet. In addition, the opening and closing plate is removed from the machine head against the magnetic force of the magnet, and the sliding plate body is slid to the left, thereby allowing the upper part of the shuttle to be opened. [Conventional technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 9-299674

[Problems to be solved by the present invention]

In the case where the engagement and disengagement structure of the opening and closing plate in the sliding plate device is applied to the engagement and disengagement structure of the needle plate of the sewing machine, for example, a magnet is arranged under the needle plate, and the needle plate is fixed by the magnetic force of the magnet On the nose. Thereby, when the needle plate is installed on the machine head, the needle plate can be attracted to the side of the machine head by the magnetic force of the magnet, and the needle plate can be installed on the machine head.

On the other hand, when the needle plate is removed from the handpiece, as described above, a releasing force resisting the magnetic force of the magnet is input to the needle plate to release the fixed state of the magnet to the needle plate. However, at this time, a certain fixing force (magnetic force) acts on the needle plate from the magnet. Therefore, when the fixed state of the needle plate is released, the needle plate may bounce off the machine head due to the release force. Therefore, when the above-mentioned engagement and disengagement structure is applied to the needle plate, the removal performance of the needle plate may be reduced.

In view of the above facts, an object of the present invention is to provide a needle plate disengagement mechanism and a sewing machine provided with the needle plate disengagement mechanism, which can improve the removal performance of the needle plate. [Technical means to solve problems]

One or more embodiments of the present invention is a needle plate engagement and disengagement mechanism. In a sewing machine in which a needle is moved up and down by a driving force of a sewing machine motor to form a stitch, the needle plate engagement and disengagement mechanism includes: a needle plate, provided The base part of the sewing machine is composed of a magnetic body; a magnet is provided under the needle plate, and the needle plate is fixed by magnetic force; and a magnetic force changing mechanism is connected to the magnet, and the magnet is connected to the magnet by actuation The needle plate moves relatively to change the magnetic force acting on the needle plate.

One or more embodiments of the present invention is a needle plate engagement and disengagement mechanism, characterized in that the magnetic force changing mechanism is provided with a rotating body, and the rotating body is formed on the lower side of the needle plate to be wound around the needle plate It rotates in a parallel axis; the magnet is provided on the rotating body so as to rotate integrally.

One or more embodiments of the present invention is a needle plate engagement and disengagement mechanism, characterized in that the magnetic force changing mechanism is provided with a push-up portion, and the push-up portion is provided on the rotating body so as to rotate integrally; When the rotating body rotates, the push-up portion pushes the needle plate upward.

One or more embodiments of the present invention is a needle plate engagement and disengagement mechanism, characterized in that the rotating body is connected to a rotating body drive mechanism; the rotating body drive mechanism is provided with an actuation mechanism for actuating the rotating body Rotating body drive motor.

One or more embodiments of the present invention is a needle plate engagement and disengagement mechanism, characterized in that the needle is prohibited when the needle is located below the top surface of the needle plate or when the sewing machine motor is actuated The rotation body drives the motor when the board is in a fixed state.

One or more embodiments of the present invention is a sewing machine including the needle plate engagement and disengagement mechanism configured as described above.

One or more embodiments of the present invention is a needle plate engagement and disengagement mechanism provided with a detection portion for detecting the up and down position of the needle; the rotating body drive motor is interlocked with the detection portion to act, and the needle is located closer to the needle When the top surface of the board is lower, the operation of the rotating body drive motor is prohibited. [Effects of the invention]

The needle plate engagement and disengagement mechanism and the sewing machine constructed as described above can improve the removal performance of the needle plate.

(First embodiment) Hereinafter, the sewing machine 10 to which the needle plate engagement and disengagement mechanism 60 of the first embodiment is applied will be described with reference to FIGS. 1 to 7. In addition, the arrow UP suitably shown in the drawing represents the upper side of the sewing machine 10, the arrow FR represents the front side of the sewing machine 10, and the arrow RH represents the right side (one side in the width direction) of the sewing machine 10. In the following description, the vertical, back-and-forth, and left-right directions are used. Unless otherwise stated, the vertical, back-and-front, and left and right of the sewing machine 10 are shown.

(Overall composition of sewing machine) As shown in FIG. 2, the sewing machine 10 as a whole has a slightly U-shape open to the left side when viewed from the front side in a front view. Specifically, the sewing machine 10 includes the following elements: a leg portion 12 that constitutes the right end of the sewing machine 10 and extends vertically; an arm portion 14 that extends from the upper end portion of the leg portion 12 to the left side; and a base portion 16. Extend from the lower end of the leg post 12 to the left. In addition, inside the sewing machine 10, a skeleton frame (not shown) constituting the skeleton of the sewing machine 10 is provided.

In addition, the sewing machine 10 includes a needle plate 62 provided on the upper left portion of the base portion 16. Further, the sewing machine 10 includes: a needle plate engagement and disengagement mechanism 60 that fixes the needle plate 62 so as to be engageable and disengageable (refer to FIG. 1 ); and a needle drive mechanism 20 that moves the needle 36 up and down (refer to FIG. 3 ). Hereinafter, each structure of the sewing machine 10 will be described.

(About needle drive mechanism) As shown in FIG. 3, the needle driving mechanism 20 includes a sewing machine motor 22, an upper shaft 26, a coupling mechanism 30, a needle bar 34, and a lower shaft 38. The sewing machine motor 22 is fixed to the frame frame with the left-right direction as the axis direction. As shown in FIG. 4(A), the sewing machine motor 22 is electrically connected to a control unit 94 described later; the control unit 94 is electrically connected to the operation unit 24. As shown in FIG. 2, the operation unit 24 is operably provided in front of the sewing machine 10 (leg part 12 ); the operation unit 24 includes a display unit and a touch panel. The operator touches the icon displayed on the operation unit 24 to output an operation signal to the sewing machine motor 22 or the needle plate motor 78 described later from the operation unit 24 to the control unit 94.

As shown in FIG. 3, the upper shaft 26 is rotatably supported by the frame base in the arm portion 14 (not shown in FIG. 3) with the left-right direction as the axis direction. In addition, a belt 28 is hung between the right end of the upper shaft 26 and the output shaft of the sewing machine motor 22 to transmit the rotational force of the sewing machine motor 22 to the upper shaft 26. In this way, the upper shaft 26 is rotated about its own axis by operating the sewing machine motor 22. In addition, the right end portion of the upper shaft 26 is connected to a pulley 29 (refer to FIG. 2 ); the pulley 29 is disposed on the right side of the pedestal portion 12 of the sewing machine 10 and is operably exposed outside the sewing machine 10. The operator can drive the sewing machine 10 (upper shaft 26) manually by rotating the pulley 29. In addition, the left end of the upper shaft 26 is connected to the crank 32 constituting the coupling mechanism 30.

The needle bar 34 is arranged on the left side of the coupling mechanism 30 with the vertical direction being the axial direction. The needle bar 34 is connected to the crank 32 of the connection mechanism 30 and is configured to move the needle bar 34 up and down by rotating the upper shaft 26. In addition, the needle 36 for sewing the object to be sewn is fixed to the lower end portion of the needle bar 34 so as to be engageable and disengageable, and the needle 36 moves up and down as the needle bar 34 moves up and down. That is, the vertical position of the needle 36 is determined according to the rotation angle of the upper shaft 26.

Specifically, as shown in FIG. 4(B), the needle 36 moves up and down between the top dead center and the bottom dead center. In addition, the needle plate 62 described later is arranged between the upper dead center and the lower dead center of the needle 36. Therefore, the needle 36 is pierced through the sewing object and penetrates the needle hole 62A of the needle plate 62 to sew the sewing object. In addition, in the following description, the phase of the upper shaft 26 when the needle tip (lower end) of the needle 36 is on the upper side with respect to the top surface of the needle plate 62 in one cycle of the upward and downward movements of the needle 36 is referred to as "release phase", The phase of the upper shaft 26 when the front end (lower end) of the needle 36 is on the lower side with respect to the top surface of the needle plate 62 is referred to as the “non-release phase”.

As shown in FIG. 3, the lower shaft 38 is rotatably supported by the frame frame with the left-right direction as the axis direction inside the base portion 16 (not shown in FIG. 3 ). In addition, a belt 40 is hung between the right end portion of the lower shaft 38 and the right side portion of the upper shaft 26, and the lower shaft 38 and the upper shaft 26 rotate in conjunction with each other. In addition, the left end of the lower shaft 38 is connected to the shuttle 44 via the gear mechanism 42. Therefore, by rotating the lower shaft 38, the shuttle 44 is configured to rotate in the axial direction from the vertical direction.

(About the base part) As shown in FIG. 2, the base portion 16 includes a cover 50 that constitutes the housing of the base portion 16, and the skeleton frame is covered by the cover 50. In addition, a hole 50A for arranging a needle plate 62 described later is formed through the upper wall of the cover 50;

As shown in FIG. 1, inside the base portion 16, a fixing plate 52 is provided on the left side of the hole 50A of the cover 50 (not shown in FIG. 1 ). The fixing plate 52 is formed in a substantially rectangular plate shape with the plate thickness direction up and down, and is connected and fixed to the frame base. On the top surface of the fixing plate 52, plate-shaped first pressing members 54 and second pressing members 56 for fixing the needle plate 62 described later are provided (broadly speaking, elements understood as "pressing members"). The first pressing member 54 and the second pressing member 56 are arranged in the front-rear direction side by side in the vertical direction, and are fixed to the fixing plate 52 by screws. In the first pressing member 54, a pressing piece 54A is integrally formed, and the pressing piece 54A is inclined upward (in the direction away from the fixing plate 52) as it goes to the right. In addition, the second pressing member 56 is also integrally formed with the pressing piece 56A configured in the same manner as the pressing piece 54A, and the pressing piece 56A is inclined upward (in the direction away from the fixing plate 52) as it goes to the right.

(About the needle plate engagement and disengagement mechanism) Next, the needle plate engagement and disengagement mechanism 60 which is the main part of the present invention will be described. As shown in FIG. 1, the needle plate engagement and disengagement mechanism 60 includes the following elements: a needle plate 62; a pair of magnets 66 for fixing the needle plate 62 to the base portion 16; and a magnetic force changing mechanism 67 for changing magnets 66 for the magnetic force of the needle plate 62; the rotating body drive mechanism 74 for actuating the magnetic force changing mechanism 67; the upper-axis phase sensor 92 as a "detection unit" (refer to FIG. 3); and the control unit 94 (refer to FIG. 4(A)).

＜About needle plate＞ The needle plate 62 is composed of a magnetic body such as iron, cobalt, nickel or its alloy, or ferrite iron. The needle plate 62 is formed in a substantially rectangular plate shape with the plate thickness direction in the up-down direction, and is arranged in the hole portion 50A of the cover 50 (refer to FIG. 2 ). A locking member 64 is provided on the bottom surface of the left end portion (the end portion on the one side in the longitudinal direction) of the needle plate 62. The locking member 64 is formed in a slightly long plate shape extending in the front-rear direction, and is fixed to the needle plate 62 by screws. A pair of front and rear locking pieces 64A are integrally formed at both ends of the locking member 64 in the longitudinal direction; the locking pieces 64A are bent slightly downward from the left end of the locking member 64 to the left . In addition, the front end of the locking piece 64A is inserted from the right side toward the fixing plate 52 between the pressing piece 54A of the first pressing member 54 and the pressing piece 56A of the second pressing member 56 to insert the locking piece 64A and the pressing piece 54A, 56A are blocked. Thereby, the left end of the needle plate 62 is fixed to the fixing plate 52 by the locking member 64.

In addition, a needle hole 62A is formed through the needle plate 62, and the needle 36 penetrates the needle hole 62A when sewing an object to be sewn by the sewing machine 10.

<About the magnetic force change mechanism> The magnetic force changing mechanism 67 includes a rotating shaft 68 as a "rotating body" and a cam 70 as a "push-up portion". The rotating shaft 68 is disposed on the lower side of the right end portion of the needle plate 62 with the front-back direction being the axial direction. The rotating shaft 68 includes a core portion 68A having a circular cross section that constitutes an axis portion of the rotating shaft 68, and a substantially cylindrical outer shaft portion 68B provided on the outer peripheral portion of the core portion 68A. In this embodiment, the core 68A is made of metal, and the outer shaft 68B is made of resin (for example, POM), and the core 68A and the outer shaft 68B are integrally formed by insert molding or the like. . Specifically, the outer shaft portion 68B is formed integrally with the core portion 68A so as to cover the front side portion (one axial side portion) of the core portion 68A. As a result, the portion on the rear end side of the core portion 68A protrudes further rearward than the outer shaft portion 68B. In addition, the part on the rear end side of the core portion 68A is rotatably supported by the skeleton frame base. Thereby, the rotating shaft 68 is configured to be rotatable about an axis parallel to the needle plate 62. In addition, the rear end portion of the core portion 68A protrudes rearward from the cover 50 (refer to FIG. 2 ).

As also shown in FIG. 6(A), the cam 70 is integrally provided at the middle portion in the longitudinal direction of the outer shaft portion 68B. The cam 70 is formed into a slightly semi-elliptical shape when viewed from the front side, and protrudes diagonally backward and downward from the outer peripheral portion of the outer shaft portion 68B. Specifically, the cam 70, viewed from the front side, has a cam surface 70A curved convexly upward and rightward; the distance from the axis of the rotating shaft 68 to the cam surface 70A is configured to follow from the base end of the cam surface 70A It becomes longer toward the front. In addition, a portion of the cam surface 70A on the base end side is arranged near the lower side of the needle plate 62 (specifically, slightly spaced downward).

In addition, in the outer shaft portion 68B, a pair of raised portions 68B1 before and after bulging upward are formed in portions other than the portion where the front end portion and the cam 70 are formed. The top surface of the raised portion 68B1 is configured as a supporting surface 68B2; the supporting surface 68B2, when viewed from the axis direction of the rotating shaft 68, is configured to be curved into a circle centering on the axis of the core portion 68A (rotating shaft 68) Curved surface (refer to Figure 6(A) for an enlarged view). In addition, in a state where the needle plate 62 is fixed to the base portion 16 by a magnet 66 described later, the bottom surface of the needle plate 62 is in contact with the bearing surface 68B2 (in the state shown in FIG. 6(A), the rotating shaft 68 will be described below This position is called "fixed position".

As shown in FIGS. 1 and 2, an operation dial 72 is provided at the rear end of the rotating shaft 68 (core portion 68A) so as to be rotatable integrally. The operation dial 72 is formed into a slightly disc shape with the front-back direction being the axial direction; the rear end portion of the rotating shaft 68 is fixed to the axial center portion of the operation dial 72. With this, the operation dial 72 is operatively arranged on the outer side (specifically, the rear side) of the cover 50 (refer to FIG. 2 ). In addition, the operator can rotate the rotary shaft 72 to rotate the rotary shaft 68 manually.

<About Magnet> As shown in FIGS. 1 and 6(A), the pair of magnets 66 are formed in a substantially rectangular column shape with the axial direction of the rotating shaft 68 as the longitudinal direction. These magnets 66 are arranged on the front side and the rear side of the cam 70, respectively, and are buried above the outer shaft portion 68B (specifically, the raised portion 68B1). Thereby, the magnet 66 and the outer shaft portion 68B (rotation shaft 68) are configured to be rotatable integrally. In addition, in a state where the magnet 66 is embedded in the outer shaft portion 68B, the top surface of the magnet 66 is exposed to the outside of the rotating shaft 68. Further, at a fixed position of the rotating shaft 68, the magnet 66 is disposed below the needle plate 62 with a predetermined gap, and the top surface of the magnet 66 and the bottom surface of the needle plate 62 are arranged to face each other in the vertical direction (refer to FIG. 6(A )'S part of the enlarged view). That is, the magnet 66 is not in contact with the needle plate 62, but is constituted by the support surface 68B2 that determines the vertical position of the needle plate 62. In addition, in the fixed position of the rotating shaft 68, the needle plate 62 is attracted downward by the magnetic force of the magnet 66, and the needle plate 62 is fixed to the base portion 16.

In addition, if the rotating shaft 68 rotates from a fixed position to one side in the direction of rotation (arrow A direction side in FIG. 6A ), the magnet 66 is displaced to the left and lower with respect to the needle plate 62, and the cam 70 moves upward from the rotating shaft 68 to the upper side The prominent position displacement, the details will be explained later. By this, the fixed state of the needle plate 62 generated by the magnet 66 is released, and the cam 70 (the cam surface 70A) pushes the needle plate 62 upward (the position shown in FIG. 6(B), and the rotating shaft 68 ( This position of cam 70) is called "release position". That is, by rotating (actuating) the magnetic force changing mechanism 67 from the fixed position to the release position, and using the magnetic force changing mechanism 67 to move the magnet 66 to the needle plate 62 relatively, changing the magnetic force of the magnet 66 acting on the needle plate 62 constitute.

<About the rotating body drive mechanism> As shown in FIG. 1, the rotating body drive mechanism 74 includes a bottom plate 76, a needle plate motor 78 as a “rotating body drive motor”, a transmission mechanism 80, and a connection mechanism 86.

[About the bottom plate] The bottom plate 76 is formed in a substantially rectangular plate shape in which the vertical direction is the thickness direction and extends in the front-rear direction. The bottom plate 76 is arranged at a distance from the right side of the rotating shaft 68; the rear end portion of the bottom plate 76 is fixed to the frame frame. A circular exposure hole 76A for exposing an output shaft 78A of a needle plate motor 78 to be described later is formed through the front portion of the bottom plate 76 at a slightly central portion in the left-right direction. In addition, a support shaft 76S is provided at the rear end portion of the bottom plate 76 to support the swing arm 84 of the transmission mechanism 80 described later in a rotatable manner. The support shaft 76S is formed in a substantially cylindrical shape with the axial direction up and down, and protrudes upward from the bottom plate 76.

[About needle plate motor] The needle plate motor 78 is arranged in the axial direction up and down, and is arranged adjacent to the lower front side of the bottom plate 76, and is fixed to the bottom plate 76 at a position not shown. Specifically, the needle plate motor 78 is arranged coaxially with the exposed hole 76A of the bottom plate 76; the output shaft 78A of the needle plate motor 78 is arranged in the exposed hole 76A. In addition, the output shaft 78A is provided with a pinion gear 82 that constitutes a transmission mechanism 80 described later, and the pinion gear 82 is disposed on the upper side of the bottom plate 76 so as to be integrally rotatable. In addition, in this embodiment, the needle plate motor 78 is configured as a stepping motor, and is electrically connected to the control unit 94 described later. Under the control of the control unit 94, the needle plate motor 78 is actuated.

[About the communication agency] The transmission mechanism 80 includes the pinion 82 and the swing arm 84 described above. The swing arm 84 is formed in a substantially fan-shaped plate shape having a plate thickness direction in a vertical direction when viewed from above, and is disposed above the bottom plate 76. At the base end (rear end) of the swing arm 84, a support hub 84A is provided; the support hub 84A is formed in a substantially cylindrical shape with the axis direction up and down. Then, the support shaft 76S of the bottom plate 76 is inserted into the support hub 84A in a relatively rotatable manner. Thereby, the swing arm 84 is rotatably supported on the support shaft 76S. In addition, the E-ring ER is locked to the front end portion (upper end) of the support shaft 76S, and the upward movement of the swing arm 84 is restricted by the E-ring ER.

At the front end (front end) of the swing arm 84, a rack portion 84B is formed; the rack portion 84B, when viewed in plan, is bent into a slightly arc shape centered on the axis of the support hub 84A (support shaft 76S), and is arranged at The pinion gear 82 of the needle plate motor 78 is behind. In addition, a plurality of rack teeth are formed in the rack portion 84B; the rack teeth mesh with the pinion gear 82. Therefore, by actuating the needle plate motor 78, the swing arm 84 swings (rotates) around the support shaft 76S. Specifically, the swing arm 84 is configured to swing (rotate) back and forth between the "first position" indicated by the solid line in FIG. 1 and the "second position" indicated by the two-dot chain line.

Further, a connection pin 84P is provided at a portion on the front end side of the swing arm 84; the connection pin 84P is formed in a substantially cylindrical shape with the axial direction in the up-down direction, and protrudes upward from the swing arm 84.

[About connection mechanism] The connection mechanism 86 includes a first connector 88 and a second connector 90 that are integrally provided at the front end portion of the rotating shaft 68 (outer shaft portion 68B). The first connector 88 is formed in a plate shape with the front-rear direction in the plate thickness direction, and projects from the front end portion of the outer shaft portion 68B to the obliquely lower left side in the front view.

The second connector 90 is formed in a slightly long plate shape extending in the left-right direction. Specifically, the second connector 90 includes a connecting portion 90L and a connecting portion 90R. The connecting portion 90R constitutes a left portion of the second connector 90 and the connecting portion 90R constitutes a right portion of the second connector 90. The connecting portion 90L has a thickness direction in the front-rear direction, and is disposed adjacent to the rear side of the first connector 88. In addition, the left end portion of the connecting portion 90L (the one end portion in the longitudinal direction of the second connecting member 90) is rotatably connected to the front end portion of the first connecting member 88 by the connecting pin P whose axial direction is the front-rear direction link.

The connecting portion 90R has a thickness direction in the upper and lower directions, and is disposed behind the connecting portion 90L. The front end of the left end of the connecting portion 90R is connected to the upper end of the right end of the connecting portion 90L. As a result, the connection portion 90R is arranged above the connection portion 90L. In addition, the right end portion (the other end portion of the second connector 90 in the longitudinal direction) of the connection portion 90R is rotatably connected to the connection pin 84P of the swing arm 84.

As a result, the second link 90 is moved back and forth in conjunction with the back and forth swing of the swing arm 84, and the first link 88 (that is, the rotating shaft 68) is rotated back and forth around the axis of the rotating shaft 68. Specifically, in the first position of the swing arm 84, the rotating shaft 68 is arranged at a fixed position, and by rotating the swing arm 84 from the first position to the second position, the rotating shaft 68 is arranged at the release position .

<About the upper-axis phase sensor> As shown in FIG. 3, the upper shaft phase sensor 92 is provided at the middle portion of the upper shaft 26 in the longitudinal direction. The upper shaft phase sensor 92 is configured as a sensor that detects the rotational phase of the upper shaft 26; in this embodiment, the upper shaft phase sensor 92 is configured as a rotary encoder as an example. Specifically, the upper-axis phase sensor 92 includes a rotating plate 92A and a phase detection unit 92B.

The rotating plate 92A is formed in a disc shape, is arranged coaxially with the upper shaft 26, and is fixed to the upper shaft 26 so as to be rotatable integrally. A plurality of slits extending in the radial direction of the rotating plate 92A are formed through the rotating plate 92A; the slits are arranged at predetermined intervals in the circumferential direction of the rotating plate 92A.

The phase detection unit 92B includes a light-emitting element and a light-receiving element (not shown). The light-emitting element and the light-receiving element are arranged to face each other in the thickness direction of the rotating plate 92A, and the rotating plate 92A is arranged between the light-emitting element and the light-receiving element. In addition, the phase detection unit 92B is electrically connected to the control unit 94 described later (refer to FIG. 4(A) ). In addition, by illuminating the light emitting element toward the rotating plate 92A, the light receiving element receives the light passing through the slit of the rotating plate 92A, and the upper shaft phase sensor 92 detects the rotation angle (phase) of the upper shaft 26 to control The part 94 outputs the configuration of the detection signal.

<About the Control Department> As shown in FIG. 4(A), the control section 94 is electrically connected to the sewing machine motor 22, the operation section 24, the needle plate motor 78, and the upper shaft phase sensor 92. Therefore, the control unit 94 is configured to control the operation of the sewing machine motor 22 and the needle plate motor 78 based on the operation signal from the operation unit 24.

Furthermore, the control unit 94 includes a determination unit 96. The determination unit 96 makes a determination to allow or prohibit the operation of the needle plate motor 78; the control unit 94 is configured to control the operation of the needle plate motor 78 based on the determination of the determination unit 96. Specifically, the judging unit 96 judges whether to permit or prohibit the operation of the needle plate motor 78 based on the phase state of the upper shaft 26 (in other words, the up and down position of the needle 36) and the driving state of the sewing machine 10.

More specifically, when the motor of the sewing machine 10 is driven by the sewing machine motor 22, the determination unit 96 performs a determination to prohibit the operation of the needle plate motor 78. In addition, the judging section 96 judges whether the rotational phase of the upper shaft 26 is the release phase or the non-release phase based on the detection signal from the upper shaft phase sensor 92 (in other words, whether the needle tip of the needle 36 is located on the needle plate 62's top surface is even lower). Then, when the sewing machine 10 is not in the motor-driven state (that is, the non-driven state of the sewing machine motor 22), and the phase of the upper shaft 26 is in the non-released phase, the judging section 96 performs judgment to prohibit the operation of the needle plate motor 78 . That is, the needle plate motor 78 acts in conjunction with the upper shaft phase sensor 92. When the sewing machine 10 is not in the motor drive state and the phase of the upper shaft 26 is in the non-released phase, the operation of the needle plate motor 78 is prohibited.

On the other hand, when the sewing machine 10 is not in the motor-driven state and the phase of the upper shaft 26 is the released phase, the determination unit 96 performs determination to allow the operation of the needle plate motor 78. If the judging section 96 performs the judgment to allow the operation of the needle plate motor 78, the control section 94 becomes the operation of the needle plate motor 78 based on the operation signal from the operation section 24 (operation signal for actuating the needle plate motor 78) Composition.

(About role and effect) Next, the operation of the needle plate engagement and disengagement mechanism 60 will be described using the flowchart shown in FIG. 5.

In the sewing machine 10 configured as described above, the rotary shaft 68 of the needle plate engagement and disengagement mechanism 60 is arranged at a fixed position, and the needle plate 62 is fixed to the base portion 16. Therefore, the top surface of the magnet 66 provided on the rotating shaft 68 is arranged close to the bottom surface of the needle plate 62, and the needle plate 62 is fixed to the base portion 16 by the magnetic force of the magnet 66 (refer to FIG. 6(A)). In this state, when driving of the sewing machine 10 is started, the operator touches the icon displayed on the operation unit 24 (step S1). As a result, the operation signal is output from the operation unit 24 to the control unit 94, and the motor drive state in which the sewing machine 10 is driven by the sewing machine motor 22 becomes. Therefore, the determination unit 96 of the control unit 94 performs determination to prohibit the operation of the needle plate motor 78 (step S2). As a result, the inoperative state of the rotating body drive mechanism 74 is maintained, and the fixed state of the needle plate 62 is maintained.

After the process of step S2, it progresses to step S3, and the operation of the sewing machine motor 22 is started by the control part 94. With this, the sewing machine 10 is changed from the stopped state to the motor-driven state, and the sewing of the sewing object is performed.

After the process of step S3, when the driving of the sewing machine 10 is stopped, the operator touches the icon displayed on the operation unit 24 (step S4). By this, the operation signal is output from the operation unit 24 to the control unit 94. Then, the control unit 94 that receives the operation signal from the operation unit 24 stops the operation of the sewing machine motor 22, and causes the sewing machine 10 to transition from the motor drive state to the stopped state (step S5).

After the processing in step S5, proceeding to step S6, the determination section 96 of the control section 94 determines the phase state of the upper shaft 26 based on the detection signal from the upper shaft phase sensor 92. Specifically, the determination unit 96 determines whether or not the phase of the upper shaft 26 is the release phase. When the phase of the upper shaft 26 is the canceled phase (when "Yes" in step S6), go to step S7. Then, in step S7, the determination unit 96 performs determination to allow the operation of the needle plate motor 78.

After the processing of step S7, proceed to step S8. In step S8, a display prompting an operation instruction for the needle plate motor 78 (rotating body drive mechanism 74) is displayed on the display unit of the operation unit 24, and the control unit 94 determines whether the icon is touched by the operation unit 24 .

Then, in step S8, when the operation instruction to the needle plate motor 78 is given (in the case of "Yes" in step S8), the process proceeds to step S9. In step S9, the control unit 94 receives the operation signal from the operation unit 24, and operates to rotate the output shaft 78A of the needle plate motor 78 in the forward direction. As a result, the needle plate engagement and disengagement mechanism 60 is actuated.

Specifically, when the operation of the needle plate motor 78 starts, the pinion gear 82 rotates together with the output shaft 78A of the needle plate motor 78. As a result, the swing arm 84 meshing with the pinion gear 82 swings from the first position to the second position. When the swing arm 84 swings from the first position to the second position, the second link 90 of the connection mechanism 86 connected to the swing arm 84 is displaced to the right. Therefore, the first link 88 connected to the second link 90 in a relatively rotatable manner is rotated to one side in the rotation direction together with the rotating shaft 68. That is, the rotating shaft 68 rotates from a fixed position to one side in the direction of rotation (arrow A direction side in FIG. 6(A)).

In addition, when the rotation shaft 68 rotates from the fixed position to one side in the rotation direction, the magnet 66 rotates to the one side in the rotation direction together with the rotation shaft 68. As a result, the magnet 66 relatively rotates (moves) to the left and downward with respect to the needle plate 62, and the magnetic force of the magnet 66 acting on the needle plate 62 changes so as to gradually become lower. That is, the fixed state of the needle plate 62 by the magnet 66 is gradually released. In addition, at this time, the cam 70 rotates together with the rotating shaft 68 in the conventional manner in which the upper side is displaced. Specifically, the base end of the cam surface 70A of the cam 70 is in contact with the bottom surface of the needle plate 62. In addition, the contact portion of the cam surface 70A of the cam 70 with the needle plate 62 changes from the base end portion of the cam surface 70A to the front end side, and the cam surface 70A slides on the bottom surface of the needle plate 62. Here, the distance from the axis of the rotating shaft 68 to the cam surface 70A is set to become longer from the base end of the cam surface 70A toward the front end. Therefore, when the rotating shaft 68 rotates, the needle plate 62 is pushed upward by the cam surface 70A. As a result, as shown in FIG. 6(B), the needle plate 62 is spaced upward from the rotating shaft 68 and removed from the base portion 16.

After the processing of step S9, proceed to step S10. In step S10, after the processing in step S9, after a predetermined time has passed, the control unit 94 actuates the needle plate motor 78 in such a manner that the output shaft 78A of the needle plate motor 78 is reversely rotated. As a result, the rotating body drive mechanism 74 is operated again. Specifically, the rotating shaft 68 (cam 70) rotates from the release position to the other side in the direction of rotation (arrow B direction side in FIG. 6(B)), and the rotating shaft 68 is again arranged at a fixed position. As a result, the needle plate engagement/disengagement mechanism 60 returns to the state where the needle plate 62 can be mounted on the base portion 16.

On the other hand, in step S8, when the operation instruction for the needle plate motor 78 is not given (in the case of "No" in step S8), the process returns to step S6, and the determination unit 96 is based on the detection from the upper-axis phase sensor 92 Signal to determine the phase status of the upper shaft 26. That is, after the sewing machine motor 22 is stopped, the operator may not remove (replace) the needle plate 62, but may operate the pulley 29 to manually sew the sewing object. Therefore, in step S8, when the operation instruction for the needle plate motor 78 is not given, the procedure returns to step S6, and the judgment part 96 performs judgment based on the rotation phase of the upper shaft 26.

In addition, in step S6, when the phase of the upper shaft 26 is a non-release phase (in the case of "No" in step S6), it progresses to step S11. In step S11, the determination unit 96 performs determination to prohibit the operation of the needle plate motor 78. As a result, the operation section 24 does not display an icon that prompts an operation instruction for the needle plate motor 78 (rotating body drive mechanism 74) (or causes the icon to be displayed in a state where it cannot be touched), and The operation instruction to the needle plate motor 78 cannot be executed. That is, the inactive state of the rotating body drive mechanism 74 is maintained, and the fixed state of the needle plate 62 is maintained. Then, after the process of step S11, it returns to step S6, and the determination part 96 repeats determination based on the rotation phase of the upper shaft 26.

Hereinafter, the operation of the needle plate engagement and disengagement mechanism 60 described in the above flowchart will be further described using the timing chart shown in FIG. 7. In addition, (1) in the timing chart of FIG. 7 shows the driving state of the sewing machine 10 and (2) shows the operating state of the sewing machine motor 22. In addition, (3) in the timing chart of FIG. 7 shows the phase state of the upper shaft 26 and (4) shows the judgment state of the needle plate motor 78 by the judgment unit 96.

In the stopped state of the sewing machine 10 (refer to the section "a" in FIG. 7), the sewing machine motor 22 is in an inactive state (OFF state). In addition, at this time, the phase of the upper shaft 26 becomes the release phase, and the needle 36 is located above the needle plate 62. Therefore, the determination unit 96 performs determination to allow the operation of the needle plate motor 78. In other words, the rotation body drive mechanism 74 is allowed to operate.

When the operator operates the operation unit 24 from the stopped state of the sewing machine 10 to start driving the sewing machine 10, the sewing machine 10 transitions from the stopped state to the motor-driven state (refer to the section "b" in FIG. 7). Therefore, the sewing machine motor 22 is actuated by the control unit 94 and transitions from the non-actuated state (OFF state) to the actuated state (ON state). Thereby, the upper shaft 26 rotates, and the needle 36 moves up and down. Therefore, the phase of the upper shaft 26 repeats alternately between the cancelled phase and the non-released phase. In this state, the determination unit 96 determines that the operation of the needle plate motor 78 is prohibited.

If the operator operates the operation unit 24 from this state to change the sewing machine 10 from the motor-driven state to the stopped state (refer to the section "c" in FIG. 7), the operation of the sewing machine motor 22 is stopped by the control unit 94, and the sewing machine The motor 22 transitions from the operating state (ON state) to the non-operating state (OFF state). In the example shown in FIG. 7, when the driving of the sewing machine 10 is stopped, the phase of the upper shaft 26 is the non-release phase. Therefore, the determination unit 96 performs determination to prohibit the operation of the needle plate motor 78 and maintains the non-operation state of the needle plate motor 78.

When the operator manually operates the sewing machine 10 using the pulley 29 of the sewing machine 10 from this state, the sewing machine 10 transitions from the stopped state to the manual driving state (refer to the section "d" in FIG. 7). In this state, the inactive state of the sewing machine motor 22 is maintained. In addition, during manual operation, the upper shaft 26 rotates, so the phase of the upper shaft 26 alternates between the non-release phase (refer to the "d1" section in FIG. 7) and the release phase (refer to the "d2" section in FIG. 7) repeat. Therefore, when the phase of the upper shaft 26 becomes the canceled phase, the judging section 96 judges that the operation of the needle plate motor 78 is allowed. Therefore, at this time, when the operator operates the needle plate motor 78 using the operation section 24, the control section 94 receives an operation signal from the operation section 24, and activates the needle plate motor 78. With this, the fixed state of the needle plate 62 is released.

On the other hand, when the phase of the upper shaft 26 becomes the non-release phase, the determination unit 96 performs determination to prohibit the operation of the needle plate motor 78. Therefore, the inactive state of the needle plate motor 78 is maintained, and the fixed state of the needle plate 62 is maintained.

As described above, the needle plate engagement and disengagement mechanism 60 is provided with a magnetic force changing mechanism 67 below the needle plate 62; the magnet 66 is provided on the rotating shaft 68 of the magnetic force changing mechanism 67 so as to be rotatable integrally. In addition, when the magnetic force changing mechanism 67 is actuated, the magnet 66 rotates together with the rotating shaft 68 of the magnetic force changing mechanism 67 and relatively rotates (moves) with respect to the needle plate 62. With this, the magnetic force acting on the needle plate 62 from the magnet 66 can be changed. Therefore, in the fixed state of the needle plate 62, by actuating the magnetic force changing mechanism 67 to move the magnet 66 away from the needle plate 62, the magnetic force acting on the needle plate 62 from the magnet 66 can be gradually reduced (fixed force). Therefore, compared with the case where the magnet 66 is not able to relatively rotate (move) with respect to the needle plate 62, the releasing force when releasing the fixed state of the needle plate 62 can be reduced. As a result of this, when the needle plate 62 is removed from the base portion 16, the needle plate 62 can be bounced from the base portion 16 immediately. Therefore, the removal performance of the needle plate 62 can be improved.

In addition, as described above, the magnet 66 is provided integrally with the rotating shaft 68 of the magnetic force changing mechanism 67; the rotating shaft 68 is configured to be rotatable about an axis parallel to the needle plate 62. Therefore, the magnetic force acting on the needle plate 62 from the magnet 66 can be changed with a simple configuration.

In addition, the magnetic force changing mechanism 67 includes a cam 70 that is integrally rotatably provided on the rotating shaft 68; the cam 70 extends from the outer peripheral portion of the outer shaft portion 68B to the outside of the rotating shaft 68. Therefore, when the rotating shaft 68 rotates from the fixed position to one side in the direction of rotation, the cam 70 can be brought into contact with the needle plate 62 and the needle plate 62 can be pushed up to the base portion 16 by the cam 70. Thereby, the convenience when replacing the needle plate 62 can be effectively improved.

In addition, the cam 70 has a cam surface 70A; the cam surface 70A is configured to be slidable on the bottom surface of the needle plate 62. In addition, the distance from the axis of the rotating shaft 68 to the cam surface 70A is configured to become longer from the base end of the cam surface 70A toward the front end. Therefore, when the rotating shaft 68 rotates from the fixed position to the release position, the needle plate 62 can be slowly pushed upward by the cam surface 70A of the cam 70. Therefore, the cam 70 can suppress the needle plate 62 from popping up, and the cam 70 can push the needle plate 62 to the base portion 16. Therefore, the removal performance of the needle plate 62 can be effectively improved.

In addition, at a fixed position of the magnetic force changing mechanism 67, the cam 70 (cam surface 70A) is spaced apart from the lower side of the needle plate 62. Therefore, in the fixed position of the magnetic force changing mechanism 67, even if the rotation shaft 68 is temporarily shifted in the circumferential direction relative to the normal position, the cam 70 can be suppressed from pushing up the needle plate 62. Therefore, the fixed state of the needle plate 62 can be maintained well. In addition, in the fixed position of the magnetic force changing mechanism 67, by disposing the cam 70 (cam surface 70A) and the lower side of the needle plate 62, the magnetic force acting on the needle plate 62 from the magnet can be reduced, so that The cam 70 (cam surface 70A) abuts on the needle plate 62.

In addition, a pair of magnets 66 extending in the axial direction of the rotating shaft 68 are arranged side by side in the axial direction of the rotating shaft 68. As a result, the magnetic force of the magnet 66 can cover the entire axial direction of the rotating shaft 68 and act on the needle plate 62. Therefore, the needle plate 62 can be fixed well by the magnet 66. In addition, on the rotating shaft 68, the cam 70 is arranged between the pair of magnets 66. Therefore, the upward thrust of the cam 70 when the needle plate 62 is pushed up against the magnetic force of the magnet 66 can be given to the needle plate 62 in a well-balanced manner.

In addition, in the fixed state of the needle plate 62, the bearing surface 68B2 of the rotating shaft 68 is disposed above the magnet 66, and the bottom surface of the needle plate 62 is in contact with the bearing surface 68B2 of the rotating shaft 68. Therefore, the up and down positions of the needle plate 62 can be determined by the bearing surface 68B2 of the rotating shaft 68, and the needle plate 62 can be fixed to the base portion 16 by the magnetic force of the magnet 66. Therefore, for example, as compared with a configuration in which the outer peripheral surface of the magnet 66 exposed from the rotating shaft 68 forms an arc surface, the needle plate 62 is in contact with the arc surface of the magnet 66, the up and down of the needle plate 62 can be accurately determined position.

In addition, the bearing surface 68B2 of the rotating shaft 68 is curved in an arc shape centering on the axis of the rotating shaft 68 when viewed from the axial direction of the rotating shaft 68. Therefore, when the rotating shaft 68 is temporarily shifted in the circumferential direction with respect to the fixed position of the rotating shaft 68, the position of the contact portion of the support surface 68B2 in the up-down direction with the needle plate 62 can be constant. Thereby, the positional deviation of the rotation axis 68 in the circumferential direction can be absorbed by the bearing surface 68B2, and the positional deviation of the needle plate 62 in the vertical direction can be suppressed.

In addition, the magnet 66 is formed in a rectangular column shape extending in the axial direction of the rotating shaft 68. With this, the magnet 66 for fixing the needle plate 62 can be manufactured at low cost.

In addition, the rotating shaft 68 includes a metal core portion 68A that constitutes the axial center portion of the rotating shaft 68 and a resin outer shaft portion 68B that constitutes the outer peripheral portion of the rotating shaft 68. In addition, the magnet 66 is embedded in the outer shaft portion 68B, and the cam 70 is formed integrally with the outer shaft portion 68B. Therefore, the strength of the rotating shaft 68 can be ensured, and the rotating shaft 68 configured to rotate integrally with the magnet 66 and the cam 70 can be manufactured at a low cost. In addition, for example, by forming the outer shaft portion 68B with a material with good slidability (POM), the cam surface 70A can be smoothly slid on the needle plate 62 when the rotary shaft 68 rotates, and the needle plate can be moved by the cam 70 62 Push up. Further, by making the outer shaft portion 68B made of resin, it is possible to suppress the abnormal sound (collision sound) between the bearing surface 68B2 of the outer shaft portion 68B and the needle plate 62 when the needle plate 62 is mounted on the base portion 16 Of generation.

In addition, the rotating shaft 68 is connected to the rotating body driving mechanism 74, and the needle shaft motor 78 of the rotating body driving mechanism 74 is operated to rotate the rotating shaft 68 between the fixed position and the released position. Therefore, the needle plate 62 can be automatically removed from the base portion 16. Therefore, it is possible to improve the convenience for the operator when the needle plate 62 is removed from the base portion 16 (when replaced).

In addition, when the sewing machine motor 22 is inactive and the needle 36 (the tip of the needle) is located below the top surface of the needle plate 62, the control portion 94 of the needle plate engagement and disengagement mechanism 60 prohibits the operation of the needle plate motor 78 . When the needle 36 is located below the top surface of the needle plate 62, the needle 36 penetrates the needle hole 62A of the needle plate 62. Therefore, in this situation, when the needle plate motor 78 is activated, the needle plate 62 is removed from the base portion 16 with the needle 36 passing through the needle hole 62A of 62. Therefore, it can be said that these conditions are not suitable for the replacement of the needle plate 62. Thus, in a situation where replacement of the needle plate 62 is not suitable, removal of the needle plate 62 from the base portion 16 is prohibited, and replacement of the needle plate 62 can be prevented. Further, when the sewing machine motor 22 is operated, the control unit 94 prohibits the operation of the needle plate motor 78. On the other hand, when the sewing machine motor 22 is actuated, the sewing object is being sewn. Therefore, this situation can be said to be a situation where the operator does not intend to replace the needle plate 62. Therefore, this situation can also be said to be a situation that is not suitable for the replacement of the needle plate 62. Therefore, in such situations that are not suitable for the replacement of the needle plate 62, the removal of the needle plate 62 from the base portion 16 is also prohibited, which prevents the replacement of the needle plate 62. With the above, the replacement of the needle plate 62 can be prevented in a situation that is not suitable for the replacement of the needle plate 62.

In addition, the needle plate engagement and disengagement mechanism 60 includes an upper shaft phase sensor 92; and the upper shaft phase sensor 92 detects the rotational phase of the upper shaft 26 that moves the needle 36 up and down. Therefore, by detecting the rotational phase (angle) of the upper shaft 26 by the upper shaft phase sensor 92, the up and down positions of the needle 36 can be easily detected. Therefore, the needle plate engagement and disengagement mechanism 60 can detect the vertical position of the needle 36 with a simple configuration.

In addition, the rotating body driving mechanism 74 includes a connecting mechanism 86 connected to the rotating shaft 68 and a transmitting mechanism 80 that transmits the driving force of the needle plate motor 78 to the connecting mechanism 86. By this, the driving force of the needle plate motor 78 is transmitted to the connection mechanism 86, and the rotating shaft 68 can be rotated between the fixed position and the released position. In addition, by using the connection mechanism 86, the needle plate motor 78 can be provided at any position in the base portion 16 separated from the rotation shaft 68.

In addition, the transmission mechanism 80 of the rotating body drive mechanism 74 includes the following elements: a pinion gear 82, which is integrally rotatably provided on the output shaft 78A of the needle plate motor 78; and a swing arm 84, provided with a pinion gear 82 meshes with the rack portion 84B; the second link 90 of the link mechanism 86 is connected to the swing arm 84 in a relatively rotatable manner. Therefore, with a simple configuration, the rotation force of the needle plate motor 78 can be converted into linear motion, and the rotation shaft 68 can be rotated back and forth by the connection mechanism 86.

In addition, as described above, the positional deviation in the circumferential direction of the rotating shaft 68 is absorbed by the bearing surface 68B2. Therefore, even if the magnet 66 for fixing the needle plate 62 is provided on the rotating shaft 68, the needle plate motor 78 does not always need to be energized to maintain the rotating shaft 68 at a fixed position. Therefore, it can contribute to the power saving of the sewing machine 10.

In addition, at the rear end of the rotating shaft 68, an operation dial 72 is rotatably provided; the operation dial 72 is operably exposed outside the cover 50. Therefore, by rotating the operation dial 72, the rotary shaft 68 can be manually rotated to release the fixed state of the needle plate 62. Therefore, for example, the needle plate 62 can be removed from the base portion 16 in an emergency such as when the needle plate motor 78 fails temporarily.

(Second embodiment) The needle plate engagement and disengagement mechanism 200 of the second embodiment will be described below using FIGS. 8 to 10. The needle plate engagement and disengagement mechanism 200 includes a magnetic force changing mechanism 210, and a magnet 66 is provided on the magnetic force changing mechanism 210. In addition, the needle plate engagement and disengagement mechanism 200 does not include the rotating body drive mechanism 74 of the magnetic force changing mechanism 67 of the first embodiment. That is, the magnetic force changing mechanism 210 is configured to be manually operable. Hereinafter, the magnet 66 and the needle plate engagement/disengagement mechanism 200 will be mainly described.

The magnetic force changing mechanism 210 includes a lever 212 as a "rotating body" and a release protrusion 214 provided as a "push-up portion" on the lever 212. The rod 212 is formed in a substantially rectangular plate shape in which the vertical direction is the thickness direction and the lateral direction is the longitudinal direction. Then, the lever 212 is arranged to be spaced from the lower right side of the needle plate 62. In addition, the lever 212 is rotatably supported in the part on the left side by the support shaft 220 whose front-back direction is the axial direction. Thereby, the lever 212 is supported so as to be rotatable about an axis parallel to the needle plate 62. In addition, both ends of the support shaft 220 in the longitudinal direction are fixed to the skeleton frame base of the sewing machine 10. Thereby, the lever 212 is configured to be rotatable about one side of the rotation direction (arrow C direction side in FIG. 10(A)) and the other rotation side (arrow D direction side in FIG. 10(B)) around the support shaft 220 axis.

In addition, on the right side of the support shaft 220, a baffle 222 (in a broad sense, an element understood as a "bearing member" in the up-down direction) is provided; the baffle 222 is fixed to the skeleton frame base of the sewing machine 10. In addition, the stopper 222 is arranged adjacent to the lower side of the right end of the needle plate 62 and supports the right end of the needle plate 62 from the lower side. In addition, at the fixed position of the rod 212 shown in FIG. 10(A), the top surface of the rod 212 on the right side of the support shaft 220 is arranged near the lower side of the baffle 222. This configuration restricts the rotation of the rod 212 at a fixed position to the other side in the direction of rotation.

The magnet 66 is formed in a substantially cuboid shape, and is fixed to the top surface of the rod 212 in a position on the right side of the support shaft 220. In the fixed position of the rod 212, the magnet 66 is arranged adjacent to the lower side of the right side portion of the needle plate 62, and is arranged on the left side of the baffle 222, and the needle plate 62 is fixed to the base portion 16 by the magnetic force of the magnet 66. Therefore, when the lever 212 rotates from the fixed position to one side in the direction of rotation, the magnet 66 relatively moves (displaces) downward relative to the needle plate 62, and the magnetic force of the magnet 66 acting on the needle plate 62 becomes low.

The release protrusion 214 is integrally provided at the left end (one end) of the lever 212, and protrudes upward from the left end. This release protrusion 214 is formed in a slightly semicircular shape that is convex upward when viewed from the front side, and extends in the front-rear direction. In addition, the release protrusion 214 is arranged near the lower side of the needle plate 62. Specifically, the release protrusion 214 is arranged at a predetermined distance from the needle plate 62. In addition, when the lever 212 rotates from the fixed position to one side (the release position side) in the rotation direction, the release protrusion 214 comes into contact with the needle plate 62. By this, the protrusion 214 is released, and the needle plate 62 is pushed up.

On the other hand, an operation portion 212A protruding upward is formed at the right end of the lever 212; the operation portion 212A is operably exposed from the operation hole 50B (refer to FIG. 9) formed in the cover 50 of the sewing machine 10. Thereby, the operator rotates the lever 212 from the fixed position to one side of the rotation direction by pushing the operation portion 212A downward. In addition, the distance from the support shaft 220 to the operation portion 212A in the longitudinal direction (left-right direction) of the lever 212 is set to be longer than the distance from the support shaft 220 to the release protrusion 214.

When the fixed state of the needle plate 62 is released, in the state shown in FIG. 10(A), the operator pushes the operation portion 212A of the lever 212 downward. As a result, the lever 212 is rotated from the fixed position to one side in the rotation direction. Specifically, the magnet 66 fixed to the lever 212 is displaced downward to be separated from the needle plate 62, and the release protrusion 214 of the lever 212 is displaced upward to approach the needle plate 62. When the lever 212 is further rotated toward one side of the rotation direction, the release protrusion 214 abuts the needle plate 62 and pushes up the needle plate 62. Then, as shown in FIG. 10(B), when the lever 212 is rotated to the release position, the right end of the needle plate 62 is pushed from the base portion 16 (not shown in FIG. 10(B)) to become the needle plate. 62 is removed from the base 16.

On the other hand, when the needle plate 62 is again installed on the base portion 16, the locking piece 64A of the locking member 64 of the needle plate 62 is inserted between the fixing plate 52 and the pressing pieces 54A, 56A, and the needle plate The right end portion of 62 is placed on the release protrusion 214 in the release position to bring it into the state shown in FIG. 10(B). At this time, the lever 212 is moved from the state shown in FIG. 10(B) to the other side in the direction of rotation by the weight of the needle plate 62 or by the operator inputting the downward operating force to the needle plate 62 Spin. As a result, the magnet 66 and the needle plate 62 are gradually brought closer, and the magnetic force acting on the needle plate 62 from the magnet 66 is gradually increased. Then, when the lever 212 further rotates to the other side of the rotation direction and reaches the fixed position, the needle plate 62 is fixed to the base portion 16 by the magnetic force of the magnet 66.

Here, in the second embodiment, the magnet 66 is provided integrally with the rod 212 of the magnetic force changing mechanism 210; the rod 212 is configured to be rotatable about the axis of the support shaft 220 parallel to the needle plate 62. Therefore, in the fixed position of the lever 212, by rotating the lever 212, the magnetic force acting on the needle plate 62 from the magnet 66 can be gradually lowered to change the magnetic force. Therefore, when the magnet 66 is configured to be unable to relatively move (displace) the needle plate 62, the releasing force when releasing the fixed state of the needle plate 62 can be reduced. As a result of this, when the needle plate 62 is removed from the base portion 16, the needle plate 62 can be bounced from the base portion 16 immediately. Therefore, in the second embodiment, as in the first embodiment, the removal performance of the needle plate 62 can be improved.

In addition, a release protrusion 214 is provided on the left end of the lever 212. As described above, when the lever 212 rotates from the fixed position to one side in the rotation direction, the release protrusion 214 is displaced upward, and the needle plate 62 is pushed up. As a result, the needle plate 62 is pushed from the base 16. Therefore, the convenience when replacing the needle plate 62 can be improved.

In addition, the release protrusion 214 of the lever 212 is arranged at a predetermined distance below the needle plate 62. Therefore, when the lever 212 rotates from the fixed position to one side in the direction of rotation, the magnetic projection 66 can reduce the magnetic force acting on the needle plate 62 and then the release projection 214 can be brought into contact with the needle plate 62. Therefore, the release force acting on the needle plate 62 from the release protrusion 214 can be reduced, and the needle plate 62 can be pushed up by the release protrusion 214.

In addition, in the second embodiment, a release protrusion 214 is provided on the left end of the lever 212, and an operation portion 212A is provided on the right end of the lever 212; the support shaft 220 supports the longitudinal direction (left and right) of the lever 212 in a rotatable manner Direction) middle part. Thereby, when the operation portion 212A is pushed, the needle plate 62 can be pushed up by the lever 212 (the release protrusion 214) by the lever principle. Thereby, the needle plate 62 can be simply pushed up by releasing the protrusion 214.

In addition, the distance from the support shaft 220 to the operation portion 212A in the longitudinal direction of the lever 212 is set to be longer than the distance from the support shaft 220 to the release protrusion 214. Therefore, the needle plate 62 can be pushed up more easily by releasing the protrusion 214.

In addition, in the left-right direction, the magnet 66 is disposed between the support shaft 220 and the operation portion 212A. That is, the distance from the support shaft 220 to the operation portion 212A is set to be longer than the distance from the support shaft 220 to the magnet 66. As a result, the operating force input to the operating portion 212A can be reduced as compared with the case where the distance from the support shaft 220 to the operating portion 212A is shorter than the distance from the supporting shaft 220 to the magnet 66. Therefore, the operability when the operator operates the lever 212 can be improved.

In addition, in the second embodiment, the needle plate engagement and disengagement mechanism 200 is configured to be manually operable, but the rotating body drive mechanism 74 of the first embodiment can also be applied to the needle plate engagement and disengagement mechanism 200 to make the lever 212, It is configured to rotate by the driving force of the needle plate motor 78. In this case, for example, in the needle plate engagement and disengagement mechanism 200, the rod 212 and the support shaft 220 are integrally rotatable; the skeleton frame of the sewing machine supports the length of the support shaft 220 in a rotatable manner Both ends in the lateral direction. In addition, one end of the first connector 88 of the connection mechanism 86 is connected to the support shaft 220 so as to be rotatable integrally. Thereby, the lever 212 can be rotated to a fixed position or a released position by driving the needle plate motor 78. Therefore, the convenience for the operator can be improved.

In addition, in the needle plate engagement and disengagement mechanism 200 of the second embodiment, when the rotary body drive mechanism 74 of the first embodiment is applied, it is also possible to replace the needle plate 62 in a situation that is not suitable for the replacement of the needle plate 62, as in the first embodiment. , The operation of the needle plate motor 78 is prohibited.

In addition, in the first embodiment, the rotating shaft 68 is connected to the rotating body drive mechanism 74. However, as in the second embodiment, the disengagement mechanism 60 may be joined to the needle plate, and the rotating body drive mechanism 74 may be omitted. That is, it may be configured to manually rotate the rotating shaft 68 so that the needle plate 62 can be engaged and disengaged from the base portion 16.

Furthermore, in the first embodiment, when the rotating shaft 68 rotates, the cam surface 70A of the cam 70 slides on the needle plate 62 to push up the needle plate 62, but the structure to push up the needle plate 62 is not Limited to this form. For example, a rod-shaped release pin protruding outward in the radial direction may be provided on the rotation shaft 68, and when the rotation shaft 68 rotates, the end portion before the release pin abuts the bottom surface of the needle plate 62, and the front end portion The needle plate 62 is pushed upward.

In addition, in the first embodiment, the rotating shaft 68 is composed of a metal core portion 68A and a resin-made outer shaft portion 68B, but the configuration of the rotating shaft 68 is not limited to this form. For example, the entire rotating shaft 68 may be made of resin or metal.

In addition, in the first embodiment, the operation dial 72 is integrally rotatable at the rear end of the rotation shaft 68, but the operation dial 72 may be omitted in the rotation shaft 68. In this case, for example, the rotating shaft 68 may be formed into a long cylindrical shape, and the rotating shaft 68 may be rotatably supported by a supporting shaft fixed to the frame frame.

In addition, in the first embodiment, in the fixed state of the needle plate 62, the top surface of the magnet 66 is arranged slightly apart from the lower side of the needle plate 62, but it may also be made the top surface of the magnet 66 and the needle plate The structure of the bottom of 62 is abutted. In this case, the top surface of the magnet 66 may be the same as the bearing surface 68B2 of the rotating shaft 68, and when viewed from the axis direction of the rotating shaft 68, it may be bent so that the axis of the rotating shaft 68 becomes The arc in the center.

In the first embodiment, the operation unit 24 of the sewing machine 10 is configured to include the display unit and the operation unit of the touch panel. Instead of this form, the operation portion 24 may be a plurality of operation buttons exposed on the outside of the sewing machine 10 in an operable manner. In this case, it may also be that when the sewing machine motor 22 is inactive and the needle 36 (the tip of the needle) is located below the top surface of the needle plate 62, or when the sewing machine motor 22 is in operation, the operation button is operated. At this time, the control unit 94 does not accept the configuration of the operation signal from the operation unit 24.

In addition, in the first embodiment and the second embodiment, the entire needle plate 62 is made of a magnetic body, but it is not necessary to make the entire needle plate 62 a magnetic body. The magnet 66 only needs to magnetize the needle plate 62. Therefore, in the needle plate 62 in the fixed state, only the portion in contact with the vicinity of the top surface of the magnet 66 may be made of a magnetic body. Therefore, for example, even if it is a resin-made needle plate 62 with a metal plate (magnetic body) attached to a part thereof, the invention can be implemented. That is, in the present invention, a part including the needle plate 62 is composed of a magnetic body.

10‧‧‧Sewing machine 12‧‧‧Peg 14‧‧‧arm 16‧‧‧Base 20‧‧‧ Needle drive mechanism 22‧‧‧Sewing machine motor 24‧‧‧Operation Department 26‧‧‧up shaft 28‧‧‧Belt 29‧‧‧Pulley 30‧‧‧ Linking organization 32‧‧‧Crank 34‧‧‧Needle bar 36‧‧‧ needle 38‧‧‧lower axis 40‧‧‧Belt 42‧‧‧Gear mechanism 44‧‧‧shuttle 50‧‧‧cover 50A‧‧‧Hole 50B‧‧‧Operation hole 52‧‧‧Fixed board 54‧‧‧First pressure member 54A‧‧‧Compression 56‧‧‧The second pressure member 56A‧‧‧Compression 60‧‧‧Needle plate disengagement mechanism 62‧‧‧ Needle plate 62A‧‧‧Pinhole 64 ‧‧‧ locking member 64A‧‧‧Locking piece 66‧‧‧Magnet 67‧‧‧Magnetic force changing mechanism 68‧‧‧rotating shaft (rotating body) 68A‧‧‧Core 68B‧‧‧Outer shaft 68B1‧‧‧Bulge 68B2‧‧‧support surface 70‧‧‧Cam (Push up part) 70A‧‧‧Cam surface 72‧‧‧Operation dial 72B‧‧‧Outside shaft 74‧‧‧Rotary body drive mechanism 76‧‧‧Bottom plate 76A‧‧‧ exposed hole 76S‧‧‧Support shaft 78‧‧‧ Needle plate motor (rotating body drive motor) 78A‧‧‧ output shaft 80‧‧‧Community 82‧‧‧pinion 84‧‧‧ Swing arm 84A‧‧‧Support Hub 84B‧‧‧Rack 84P‧‧‧Link pin 86‧‧‧Connecting mechanism 88‧‧‧The first connector 90‧‧‧ 2nd connector 90L‧‧‧Connection 90R‧‧‧Connection 92‧‧‧Upper shaft phase sensor 92A‧‧‧Rotating plate 92B‧‧‧Phase Detection Department 94‧‧‧Control Department 96‧‧‧Judgment Department 200‧‧‧ Needle plate engagement and disengagement mechanism 210‧‧‧Magnetic force changing mechanism 212‧‧‧rod (rotating body) 212A‧‧‧Operation Department 214‧‧‧Remove the protrusion (Push up part) 220‧‧‧Support shaft 222‧‧‧Baffle ER‧‧‧E-ring P‧‧‧Link pin

Fig. 1 is an exploded perspective view showing a needle plate engagement and disengagement mechanism according to the first embodiment. Fig. 2 is a perspective view of the entire sewing machine to which the needle plate engagement and disengagement mechanism of the first embodiment is applied viewed obliquely from the front right. Fig. 3 is a schematic diagram of the driving mechanism of the sewing machine shown in Fig. 2. 4(A) is a block diagram of the sewing machine shown in FIG. 2; FIG. 4(B) is a graph showing the up and down positions of the needle corresponding to the rotation angle of the upper shaft. Fig. 5 is an operation flow of the needle plate engagement and disengagement mechanism in the first embodiment. 6(A) shows a front view of the fixed state of the needle plate shown in FIG. 1 viewed from the front; FIG. 6(B) shows a state where the rotation axis of the needle plate engagement and disengagement mechanism is shown in FIG. 6(A) Front view of the state of rotating to the release position and pushing up the needle plate. Fig. 7 is a timing chart of the needle plate engagement and disengagement mechanism according to the first embodiment. Fig. 8 is an exploded perspective view showing the needle plate engagement and disengagement mechanism of the second embodiment. 9 is a perspective view showing the entire sewing machine to which the needle plate engagement and disengagement mechanism of the second embodiment is applied viewed obliquely from the front right. 10(A) is a front view showing the fixed state of the needle plate shown in FIG. 8 viewed from the front side; FIG. 10(B) is a rotation axis showing the mechanism for engaging and disengaging the needle plate from FIG. 10(A). Front view of the state where the state is rotated to the release position and the needle plate is pushed up.

52‧‧‧Fixed board

54‧‧‧First pressure member

54A‧‧‧Compression

56‧‧‧The second pressure member

56A‧‧‧Compression

60‧‧‧Needle plate disengagement mechanism

62‧‧‧ Needle plate

62A‧‧‧Pinhole

64 ‧‧‧ locking member

64A‧‧‧Locking piece

66‧‧‧Magnet

67‧‧‧Magnetic force changing mechanism

68‧‧‧rotating shaft (rotating body)

68A‧‧‧Core

68B‧‧‧Outer shaft

68B1‧‧‧Bulge

68B2‧‧‧support surface

70‧‧‧Cam (Push up part)

70A‧‧‧Cam surface

72‧‧‧Operation dial

74‧‧‧Rotary body drive mechanism

76‧‧‧Bottom plate

76A‧‧‧ exposed hole

76S‧‧‧Support shaft

78‧‧‧ Needle plate motor (rotating body drive motor)

78A‧‧‧ output shaft

80‧‧‧Community

82‧‧‧pinion

84‧‧‧ Swing arm

84A‧‧‧Support Hub

84B‧‧‧Rack

84P‧‧‧Link pin

86‧‧‧Connecting mechanism

88‧‧‧The first connector

90‧‧‧ 2nd connector

90L‧‧‧Connection

90R‧‧‧Connection

ER‧‧‧E-ring

P‧‧‧Link pin

Claims (6)

A needle plate engagement and disengagement mechanism. In a sewing machine in which a needle is moved up and down by the driving force of a sewing machine motor to form stitches, the needle plate engagement and disengagement mechanism includes: The needle plate, which is installed on the base part of the sewing machine, is composed of a magnetic body; A magnet, which is arranged under the needle plate and fixes the needle plate by magnetic force; and The magnetic force changing mechanism is connected with the magnet, and the magnet is relatively moved to the needle plate by action to change the magnetic force acting on the needle plate. For example, the needle plate engagement and disengagement mechanism in item 1 of the patent scope, in which The magnetic force changing mechanism includes a rotating body, the rotating body is below the needle plate, and is configured to rotate around an axis parallel to the needle plate; The magnet is provided on the rotating body so as to be rotatable integrally. For example, the needle plate engagement and disengagement mechanism in item 2 of the patent scope, in which The magnetic force changing mechanism includes a push-up portion, and the push-up portion is provided on the rotating body so as to be rotatable integrally; When the rotating body rotates, the push-up portion pushes the needle plate upward. For example, the needle plate engagement and disengagement mechanism of item 2 or 3 of the patent scope, in which The rotating body is connected with the rotating body driving mechanism; The rotating body driving mechanism includes a rotating body driving motor, and the rotating body is actuated by the operation of the rotating body driving motor. For example, the needle plate engagement and disengagement mechanism of item 4 of the patent application scope, in which When the needle is located below the top surface of the needle plate, or when the sewing machine motor is in operation, the rotation of the rotating body drive motor in the fixed state of the needle plate is prohibited. A sewing machine includes a needle plate engagement and disengagement mechanism according to any one of items 1 to 5 of the patent application.

Images